1. Field of the Invention
The present invention relates to a magnetic head slider used for a magnetic disk device or the like and a method for producing the same, more specifically to a magnetic head slider having an air bearing surface opposed to a recording medium and arranged generally in parallel to a head element layer, and a method for producing the same, wherein the magnetic head slider is formed on a substrate in such a manner that, after forming a sacrificial layer on a substrate, a protective film layer, an adhesion layer, a head element layer and an air bearing surface layer are sequentially formed thereon, and finally a slider body is formed by a plating; the magnetic head slider being separated from the substrate by the removal of the sacrificial layer.
2. Description of the Related Art
In recent years, it has been desired to further miniaturize a head element and a magnetic head slider in accordance with a recent demand for high density magnetic recording. To meet such a demand, a method for producing a miniaturized magnetic head slider which needs little machining and is easily assembled, has been required.
For the above reason, a method for producing a magnetic head slider which needs little machining has been proposed in the prior art (for example, in Japanese Unexamined Patent Publication (Kokai) No. 8-235527. "Thin Film Magnetic Head Slider and Method for Producing the Same").
The method disclosed in the specification of the above document is as follows:
A sacrificial layer is formed on a substrate by an Al film or the like, and a head element layer and an air bearing surface layer are sequentially formed. Then, a slider body is formed by means of a plating via a plating base, resulting in a magnetic head slider on the substrate. Next, the sacrificial layer is removed by means of an etching or the like to separate the magnetic head slider from the substrate. In this regard, if the sacrificial layer is made of Al, it is removable by an aqueous solution of KOH. Thereafter, the magnetic head slider is mounted to a suspension.
During the production of the magnetic head slider mainly by means of a film formation technology while excluding the machining process, as described above, bubbles (hydrogen H.sub.2) are liable to be generated in a process for removing the sacrificial layer (such as Al film) by an etching (using an aqueous solution of KOH or the like) and thus separating the magnetic head slider from the substrate, due to the chemical reaction of the sacrificial layer with the etching liquid. Such bubbles push the periphery of the slider body upward to cause a force for forcibly releasing the air bearing surface layer (for example, made of SiO.sub.2) which has not yet been separated from the substrate. If the air bearing surface layer is not durable to such a force, there might be a risk in that the air bearing surface layer breaks or cracks.
When the magnetic head slider comes into contact with or impinges on the recording medium while flying above the recording medium in the magnetic disc device, the slider receives an impact. If the slider is not durable to the impact, there might be a risk that the air bearing surface layer breaks or cracks, or the slider body (plated, for example, with nickel) might be dented and become inoperative.